ΔE 6.1, close: similar, with a visible difference side by side. Our swatches for the two are almost the same. They are different kinds of paint: Citadel Stormhost Silver is a metallic and Scale75 Pearl Grey is a pearl paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). The swatches are almost the same. They are different kinds of paint.
The same difference applies the other way round.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Stormhost Silver on the colour wheel See Pearl Grey on the colour wheel
All matches: Stormhost Silver equivalents · Pearl Grey equivalents